Hard to tell from the pic, but I believe it may be Brooklynella. The treatment for this would be a formalin treatment either in the qt
tank, or as a SW
bath. I had a heni with this disease in qt
and the formalin baths did a good job.
Here is more info.
Look around and see if this looks at all like it.
A few other questions first.
Is he still in qt
What are the water parameter, PH
, nitrate, nitrite, ammonia?
Possibility of an injury?